Butadiene such as 1,3-butadiene has been used as a raw material of styrene-butadiene rubber (SBR) and the like.
In general, butadiene is purified from a C4 fraction produced as a by-product when synthesizing ethylene from petroleum.
In recent years, bioethanol synthesized from raw materials derived from biomass has attracted attention as an alternative to petroleum.
For example, in Patent Document 1, a method for producing butadiene in which butadiene is synthesized from ethanol (and acetaldehyde) by bringing ethanol (and acetaldehyde) into contact with a specific catalyst has been proposed. The invention of Patent Document 1 attempts to improve the production efficiency of butadiene by increasing the selectivity of butadiene.